Bale of springs



p 1942- 4 F. R. ZIMMERMAN 2,294,706

BALE OF SPRINGS Filed May 8, 1939 Patented Sept. 1, 1942 i1 siren STAT 1price 3 Claims.

The main object of the present invention is to provide a method forpreserving the uniform resiliency of a flat spring ribbon of either theordinary unbroken type-exemplified in clock springs, or the skeletontype exemplified by wire bent to zig-zag form used extensively in theupholstery art.

A further object of the invention is to so carry out the method of thisinvention as to facilitate the baling of a plurality of bent fiatsprings of the same or different lengths to provide a substantiallycylindrical bale thereof wherein the component elements are slightlynested into each other.

It has been the common practice in the art to which the inventionrelates to form long flat strips of resilient ribbon stock into spiralrolls simulating a fully contracted clock spring with the portions ofthe flat springs in the innermost portion of the roll of appreciablysmaller radius than the outer portions, the radii of the severalconvolutions of the roll increasing progressively from its inner to itsouter portion.

It has been common practice to first form the rolls of the metal stripsand then subject said rolled-up strips to heat treating to set the metalat the same time that it is hardened.

Thus when the metal is unrolled and cut into lengths, the pieces firstcut from the roll possess a far longer radius of curvature than thoseout from the inner portion of the roll.

In the upholstery art the fiat springs of given length are initially seton a short radius and are forcibly expanded to a long radius as theirends are suitably anchored to opposite rails of a furniture unit, suchas a seating unit, furniture back, or box springs for beds, the saidsprings being arched over the open spaces between the elements or railsto which the ends of the same are anchored.

The difference in the initial radius of the springs so cut from the rollobviously changes their respective load-resisting characteristics whenthey are expanded to form the aforesaid arches of equal length andheight.

The only advantage in disposing the long strip in clock-spring likerolls is compaction thereof to occupy minimum space and reducetransportation costs and also to effect economy of storage space, butthese advantages are outweighed by the aforesaid disadvantages.

In the accompanying drawing, illustrating a bale of springs constructedin accordance with the method of this invention,

wire taken on the horizontal plane of the axis of the bale.

Fig. 2 is a fragmentary detail sectional view of the same on an enlargedscale taken on the line 22 of Fig. 1.

Fig. 3 is a fragmentary transverse sectional view of the bale, on anenlarged scale, taken on the line 3-3 of Fig. 1.

Fig. 4 is an end elevation of a bale -of flat strip or ribbon stock madein accordance with the method of this invention.

Fig. 5 is a fragmentary side elevation of the same partly in centralvertical section.

Referring first to Fig. 5, it will be noted that the flat spring orribbon stock I is wound helically on a light or small pitch about anaxis to form a substantially cylindrical bale 2 wherein the ribbon l isdisposed in successive coils, each of which overlaps the next precedingcoil over substantially half the width of said ribbon stock. In theinstance illustrated in Fig. 5, the bale is composed of a single stripor ribbon of said material, but the bale may be composed of a pluralityof strips of ribbon stock I to form a plurality of short bales, each ofwhich is nested at one or both ends into or over contiguous similarsmall bales.

The customary practice in the art is to first bend the ribbon of metalabout an axis so that every point in the stock is substantiallyequidistant from the said axis. Upon completion of a bale of stock ofgiven length, the whole bale is suitably heat treated to harden and setthe Fig. 1 is a plan section of a bale of zig-zag ribbon stock while thesame is maintained in the condition to which it has been previouslybent, as aforesaid.

If the ensuing bale is composed of a single strip of ribbon stock, thengiven lengths of said stock will be unwound from the bal and cut fromthe latter for use in the production of furniture units, such as springassemblies wherein the strips of the ribbon stock are secured at theirends to a suitable frame, as for example, the frame of a chair seat. Inso doing, the substantially circular strips of the ribbon stock areincreased accordingly in radius to provide relatively shallow archeswhich span the opening in the frame to which the ends of the strips ofstock are suitably secured.

By bending all of the strips and setting them at the same initial smallradius, it will be obvious that when said strips are incorporated into aseating unit, for example all of them will offer the same degree ofresistance to load and thus provide a composite unit wherein a number 01said strips are disposed side by side, which is of uniformload-resisting capacity throughout the area occupied by said strips.

In baling the substantial equivalent of flat strips of metal,exemplified by a wire or wires 3 bent to zig-zag form, as clearlyillustrated in Fig. 1, the same method of bending the skeleton flatsprings thus formed of said Wire to form a helix is followed. Said balecomprises a succession of helical coils 4 of small pitch wherein theopposed substantially cylindrical faces of each coil 3 of said wire aredisposed at an incline of very few degrees to the axis of the bale.

In the instance illustrated, for example, the coils overlap each other adistance equal to about half the width of strip of zig-zag wire and insuch case, the inclination of the inner and outer faces of the strip tothe axis of the bale will be only a very few degrees. The extent of theoverlap of each coil of the helix upon the next succeeding coil orconvolution may be changed and varied as desired, but should be uniformthroughout the length of the bale.

This slight inclination of said inner and outer faces of the strip tothe axis of the bale does not in any manner affect relative positions ofsaid flat faces of the strips to become flush with each other whenmounted upon a frame, such as a chair seat, as aforesaid, so that bothside edges of each strip, when mounted upon a chair seat, or the like,will be horizontally aligned with each other in the direction parallelwith the axis of the arc or arch of the several springs so mounted upona frame.

A further advantage of the structure lies in the fact that by bendingthe strip or strips to a relatively small radius, compared to that ofthe arches of a chair seat subsequently formed thereby, a compact baleof the strips is formed which may be of such length as to equal, forexample, the width of a freight car or truck in which the bales are tobe transported.

Generally speaking, furniture manufacturers order the springs cut togiven lengths and to be delivered to them in such lengths. An order mayspecify one-thousand springs of one length, two-thousand of another,etc. The method of bending and baling the strips is accomplished easilyby a machine which also disposes the strips or springs into the nestedrelation to each other which forms the bale.

In many instances the strips are so short as to approximate in lengththe circumference of the bale while other strips are of a length equalto several times the circumference of the bale. By bending the strips ofall different lengths to the same helical contour and diameter, thebaling thereof as well as maintenance of uniform resiliency isfacilitated.

I claim as my invention:

1. A substantially cylindrical bale of springs of the type specifiedcomprising a series of armate and slightly and equally helical springsnested consecutively into each other, the average diameter and pitch ofall of said springs being the same and the flat faces thereof extendingequi-angularly to a common axis.

2. A substantially cylindrical bale of springs of the type specifiedcomprising a series of helical springs of equal pitch nestedconsecutively into each other, one side of each of said springs being ofsmaller radius than the other side edge of the same of a distancesubstantially equal to three times the thickness of the metal of whichthe spring is composed.

3. A flat sinuous wire spring of helical contour and uniform pitch andaverage diameter throughout its length and having its fiat facesdisposed equiangularly to the axis of the helix formed thereby, thepitch of the latter and the angle of said faces to said axis being suchthat the inner and outer faces of the spring overlap each other oversubstantially half the width of the spring.

FRED R. ZIMMERMAN-

